Biomass-based solar evaporation: Sustainable solutions for efficient and eco-friendly water supply

[Display omitted] •An all-biomass based interfacial evaporation is developed with efficient evaporation rate of 3.77 kg m−2 h−1.•The substrate exhibits a high water absorption rate of 10 g g−1 with low thermal conductivity of 0.113 W m−1 K−1.•The evaporator fabrication processes are eco-friendly without any organic solvents, strong acids, or bases. Biomass materials with features of low-cost, environmentally friendly, and renewable have received significant attention in the field of solar-driven evaporation. However, their evaporation flux is far behind than those of petroleum-based evaporations, owing to the non-rational design of water supply and thermal insulation. Herein, an efficient biobased solar evaporation is developed using konjac-derived aerogel as water transport material and bamboo-derived carbon black as photothermal material. By the means of morphology optimization and structural dimensional design, the biobased evaporator exhibits excellent water supply with water absorption ratio of 10 g g−1 and good thermal insulation with low thermal conductivity of 0.113 W m−1 K−1. As a result, the all-biomass interfacial evaporation achieves an optimal evaporation flux of 3.77 kg m−2 h−1 with photothermal conversion efficiency of 97.2 % under 1-sun illumination, representing one of the best results of biomass based solar evaporation so far. More importantly, the fabrication of evaporators is environmentally friendly without any involvement of organic solvents, strong acids, or strong bases, which satisfy the demands for sustainable development and green society.